Cash register



March 31, 1942. LEHMAN 2,278,272

' CASH REGISTER Filed Mafch 5, 194].

. m FIG. 2 48 g l Laure N. Lehman nventor His Attorney- Patented Mar. 31, 1942 CASH REGISTER Laurence N. Lehman, Dayton, Ohio, assignor to The National Cash Register Company, Dayton, Ohio, a corporation of Maryland Application March 5, 1941, Serial No. 381,781

9 Claims.

The present invention relates to improvements in cash registers'and accounting and analogous business machines, and is particularly directed to improvements in the latches for the differential mechanisms of machines of the type disclosed in Letters Patent of the United States No. 1,619,796, No. 1,747,397, and No. 1,761,542, issued, respectively, March 1, 1927, February 18, 1930, and June 3, 1930, to B. M. Shipley.

Broadly it is an object of this invention to pro fde an improved latch mechanism for the differential devices of machines of the character referred to above.

A more specific object is the provision of positive-acting latch mechanisms for the differential devices of machines of the character referred to above, said latch mechanisms also being provided with an easy unlatching action to facilitate the positioning of the differential devices.

Another object is to provide the differential mechanisms of machines of the character referred to above with improved latch mechanisms which positively lock said differential mechanisms to their driving means, said latch I mechanisms, although positive, adapted to be unlatched with a minimum of mechanical effort, to facilitate the positioning of the differential mechanisms under influence of the depressed amount keys or the totalizer wheels.

With these and incidental objects in view, the invention includes certain novel features of construction and combinations of parts, the essen-' tial elements of which are set forth in appended claims, and a preferred form or embodiment of which is hereinafter described with reference to the drawing which accompanies and forms a part of this specification.

In the drawing:

Fig. 1 is a fragmentary side elevation, as observed from the right of the machine, showing the differential mechanism for one denominational order and the improved latch mechanism therefor, said parts being shown in home position.

Fig. 2 is a top plan view of a part of the mechanism shown in Fig. ,1.

Fig. 3 is a detail view, partially sectioned, showing the side spacing of the different parts of the improvedlatch mechanism.

Fig. 4 is a side elevation, similar to Fig. 1, but showing thediflerential mechanism and the improved latch mechanism after they have been positioned under influence of a depressed amount key.

Fig. 5 is a side elevation, as observed from the right of the machine, showing in detail the structure of the improved latch mechanism.

I Description The present invention is directed to an m proved latch mechanism for latching the diflerential devices of machines of the type disclosed in the Shipley patents referred to hereinbefore to their driving mechanisms. The problem in connection with differential latches of this nature always has been to provide a latch which forms a safe operating connection between the differential mechanisms and their driving segments, and, in addition, said latch should have an easy unlatching action, so that it may be unlatched with a minimum of mechanical effort, in order to insure the proper positioning of the differential mechanisms under influence of the depressed amount keys or under influence of the totalizer wheels.

The present invention satisfactorily solves the above problem by providing a latch mechanism which positively connects the differential mechanism to its driving segment, said positive connection being formed by a blocking means that normally blocks disengaging or unlatching movement of the latch." The latch blocking means moves in unison with the differential mechanism and remains eflective during the positioning movement of said differential mechanism and until further movement of one portion of said blocking means is obstructed either by a depressed key or by the long tooth on the corresponding totalizer wheel. This obstructing of the movement of one portion of the blocking means permits the other portion to move independently thereof until the two blocking portions are disengaged from each other. The disengaging of the blocking portions unlocks the latch mechanism, whereupon camming surfaces formed on the driving segment and the portion of the latch engaged therewith force said latch to disengaged position to position the differential mechanism in proportion to the depressed amount key or the corresponding totalizer wheel.

Only the portion of the diflerential mechanism necessary for the proper explanation of the improved latch mechanism has been disclosed herein, and further disclosure is believed unnecessary, as reference may be had to the Shipley patents mentioned above for a full showing and explanation of this standard type of differential mechanism, which, through prolonged usage, has become well established in the art.

Referring to Figs. 11:0 5 inclusive of the drawarrears lag, the differential mechanism for one denomential mechanism and the driving segment 31.

The arm (Figs. 1, 4, and 6) has thereon a rounded surface adapted to engage the lower end of the stem of any one of a series of depressibie amount keys ll for this particular order, when such amount key is depressed. The amount keys II are mounted in a key framework similar to that shown in Fig. 8 of the Bhipley Patent No. 1,819,796.

Depressing any one of the amount keys 4| 1 I moves the lower end of the stem thereof into the of gear segments 2|, which actuate the corresponding totalizer wheels on the various totalizer lines. Also secured between said plates 2| and 2' is a differential latch support plate 21.

The plates 2|, 2!, and 21 (Figs. 1, 3, 4, and 5) have secured therein studs 2| and 29, the stud 2| rotatably supporting a bushing secured in an arm II and the stud 29 having iournaled thereon an arm 32. The upper ends of the arms 3i and 82 are pivotally connected to a differential latch 1 83 and support said latch for parallel shifting movement. A spring N (Fig. 1), tensioned between the latch II and the actuator 2|, urges said latch rearwardly to normally maintain an angular camming surface 3! on a foot-shaped extension thereof in engagement with a similar camming surface 3| on a differential driving segment I'I free on the bushing 22.

A link 3| operatively connects the segment 31 to an operating mechanism, not here shown but similar in every respect to that shown for the differential driving segment 36! in Fig. 8 of the Shipley Patent No. 1,619,796. The operating mechanism for the segment 31, including a cam lever connected to the link 3| and companion plats cams, imparts an invariable oscillating movement to said segment 31 each machine operation, the first movement being in a clockwise direction. v

'bajcircurmerenual surface of the hub :0 (Figs. 3'Ja'ndi'5) rotatably'supports a hub 3| se- 4| carrying a stud ll, which ex-' tends through a notch 42, formed by the bifurcated forward end of the plate 21, and thence into a slot ll in a forward extension of a latchoperating spider ll free on the hub 2|. A spring 4| (Fig. 1), tensioned between the plate 21 and the spider l4, urges said parts coimter-clockwlse and clockwise, respectively, to cause the slot II in said spider, in cooperation with the stud I I, to urge the arm 4| clockwise to normally maintain said stud II in engagement with the upper surface of the notch 42, which notch is adapted to limit the rocking movement of said arm in either direction. The arm II, the stud ll, the

notch 42, the slot 4|, and thespring ll form a yieldable lost-motion connection between the actuator 2| and the spider 4|.

path of the rounded surface 4|, as shown in Fig. 4, and, upon machine operation, the driving segment 31, during its initial movement clockwise and through the connection formed by the latch 38, carrim the differential actuators 2| and the spider 4| clockwise in unison therewith until the surface ll moves into engagement with the stem of the depressed key 49. This immediately arrests clockwise movement of the spider 44.

However, the lost-motion connection formed by the stud ll and the notch 42 in the plate 21 permits the differential actuator 2| to move clockwise independently of the spider 44 until the stud I1 is moved upwardly out of the path of the projecting finger 4|. Immediately after the stud II has moved out of the path of the flnger N, the stud ii in the arm 40 contacts the'lower surface of the notch 42 to prevent further clockwise movement of the actuator 2|, whereupon the camming surface it on the segment 81, in cooperation with the similar surface II on the foot of the latch ll, forces said latch forwardly against the action of the spring 34 to disconnect said actuator 2| from the driving segment 31 and to simultaneously engage a foot-shaped forward extension ll (Figs. 1, 4, and 5) of said latch with the corresponding one of a series of alining notches ii in an alining plate I2 supported in the usual manner by the left-hand differential hanger plate. During forward disengaging movement of the latch 32, the stud l1 moves into a clearance recess 58, as shown in Fig. 4.

After the actuator 2| has thus been positioned, the segment 31 continues its clockwise movement without interruption, causingan arcuate surface [4 thereon to pass opposite the sole of the footshaped right-hand extension of the latch ll to lock said latch in the corresponding notch II to prevent displacement of said actuator 2|.

The amount keys 49 are used only in adding and subtracting operations, and, in such operations, after the segment 31 has completed its initial movement clockwise, the correspondin wheel of the selected totalizer is engaged with I the corresponding set of teeth 2| on the actuator When the differential mechanism is in home position, as shown in Fig. 1, the spring I! maintains the actuator II and the spider N in the relative positions here shown. in which positions a projecting finger 4| on said spider 44 is maintained in the path of a flat surface on a stud l1 secured in the lower end of the arm II (Figs. 1. 3. and 5) to form a positive obstruction against coimter-clockwise movement of said arm and disengaging movement forwardly, or toward the left, of the latc l lirirlfl is insures that the camming surface 35 on said latch is'maintained in engagement with the camming surface 36 to form a positive driving connection between the differ- 7 2|. During return movement counter-clockwise of the segment 21, the arcuate. surface it moves out of the path of the sole'of the foot-shaped extension of the latch 33, and the angular shoulder formed on the periphery of said segment by the camming surface 2| moves opposite the corresponding surface ll, whereupon the spring 34 immediately shifts said latch 33 rearwardly, or towards the ri ht, to engage the camming surfaces I! and 1| and to move the stud I! beyond the finger 4|. Immediately thereafter, the

spring 4! moves the spider 4| clockwise to again place the projection I in the path of the stud 41, as shown in Fig. l, to form a positive driving connection between the actuator 2| and these!!- ment 21. Simultaneously with the engaging of the surfaces 35 and 38, a shoulder 55 (Figs. 1 and 4) on thevsegment 31 engages a stud 5| carriedby the actuator 20 and returns said actuator amazes counter-clockwise in unison therewith to home position, as shown in Fig. 1. The return movement counter-clockwise of the actuator 20 is proportionate to the value of the depressed amount key 43, and such movement rotates the engaged totalizer wheel a like distance to enter therein an amount corresponding to the value of said depressed amount key.

It will be recalled that relative movement of the actuator 20 and the spider 44 is determined by the notch 42 in the forward end of the plate 21 in cooperation with the stud 4|. When the differential mechanism is in normal or home position, as shown in Fig. 1, the spring 45 retains the stud 4| in engagement with the upper surface of said notch 42, and, when said latch 33 is disengaged from the drive segment 31, as shown in Fig. 4, said stud engages the lower surface of said notch 42.

In adding and subtracting operations when no amount key 49 is depressed, a zero stop pawl, not shown here but well known in the art and illustrated in Fig. 8 of the Shipley Patent No. 1,619,796. engages the forward extension of the spider 44 to disengage the latch 33 in exactly th same manner as the depressed amount key 43 disengages said latch, to locate the actuator 20 in zero position.

In adding and subtracting operations, the segment 31 (Figs. 1 and 4) receives one excursion of movement, asexplained above. and, in subtotal and total printing operations, said segment receives two such excursions of movement, the first of these excursions being an idle movement, which occurs while the interspersed totalizers are being shifted laterally to select the desired set of wheels thereon. During the idle movement of the segment 31, the zero stop pawl disengages the latch 33 in zero position, and, prior to the beginning of the second excursion of movement of said driving segment 31, the zero stop pawl for this particular order is rocked out of the path of the forward end of the spider 44, and, at the same time, the corresponding wheel of the selected totalizer is moved into engagement with the corresponding teeth 23 of the actuator 20. Initial movement clockwise of the actuator 20. under influence of the segment 31, causes the teeth 26 to reversely rotate the cor responding wheel of the selected totalizer until a long tooth on said wheel rocks an obstruction, not shown here but fully disclosed in the abovementioned Shipley patents, into the path of the correspondin one of a series of internal teeth 51 on the spider 44 to position said spider in proportion to the amount on said totalizer wheel.

This termination of the clockwise movement of the spider 44 by means of the slot 43 in operation with the stud 4| (Flgs. 1 and 4) disengages the latch 33 in exactly the same manner as the amount keys 49 disengage said latch in adding and subtracting operations, to position the actuator 20 in proportion to the amount standing on the selected totalizer wheel. The usual beam mechanism transmits the positioning of the actuator 20 in adding, subtracting. and sub-total and total printing operations to the printing mechanism to cause the amounts to be recorded.

The long tooth of the selected totalizer wheel corresponds to the zero position of said wheel; consequently, the actuator 20 reversely rotates said wheel from its set position to zero position. In total printing operations, the selected totalizer vheel is disengaged from the corresponding teeth 23 prior to return movement counter-clockwise of the actuator 20, and consequently said wheel remains in a zeroized condition. In sub-total printing operations, the selected totalizer wheel re- 41, forms a positive locking connection between the latch 33 and the driving segment 31, which connection can only be unlocked or broken by the interruption of clockwise setting movement of said spider 44, either by a depressed amount key 43 in adding and subtracting operations or by means of the long tooth of the selected totalizer wheel in sub-total and total printing operations. This positive locking of the latch 33 prevents any interference with the clockwise movement of the actuator 20, either from frictional drag or from minor obstructions, from prematurely disengaging said latch 33 and effecting an erroneous positioning of said actuator 20. While the latch 33 is positively locked against accidental disengagement, still the novel structure of this improved mechanism permits said latch to be disengaged under influence of the depressed amount key or the selected totalizer wheel, in the manner explained above,'with the expenditure of a minimum amount of mechanical effort, such effort being much less than that required for the disengaging of former latches of conventional construction. In fact, after the stud 41 moves above the projection 46. the camming surfaces 35 and 36 assist in the disengaging of the latch 33 instead of retarding such disengaging, due to frictional drag. as was the case with former latches. in which the connecting surfaces formed a looking connection rather than a camming connection.

Therefore, it is believed that it .is too obvious for further elaboration that the above specification discloses a novel latch mechanism which forms a positive driving connection between the differential mechanism and its driving means.

which mechanism at the same time is easily disengaged or unlocked when the differential mechanism arrives in selected position. and that said improved latch mechanism, due to itsmany novel features of construction and operation, constitutes a substantial advancement in the art.

While the form of mechanism herein shown and described is admirably adapted to fulfill the objects primarily stated. it is to be understood that it is not intended to confine the invention to the one form or embodiment disclosed, for it is susceptible of embodiment in various forms all coming within the scope of the claims which follow.

What is claimed is:

1. In a device of the class described, the combination of a driving member: a driven member; a latch carried by the driven member and coacting with the driving member to connect the driven member to the driving member; means yieldably connected to the driven member to block the latch against unlatching movement and; means to arrest motion of the blocking means. as the driven member continues to move. to unblock the latch. said driving member effective after the latch is unblocked to move said latch to disconnect the driven member from the driving member.

2. In a device of the class described, the combination of a driving member; a driven member; a latch to connect the driven member to the driving member; means carried by the driven member to shiftably support said latch on the driven member; a projection on the connecting means; an element adapted to cooperat with the projection to normally obstruct the latch against unlatching movement; a yieldable connection between the element and the driven means; and means to arrest motion of the element whereupon the yieldable connection permits the driven member to move after the element has been arrested to move the projection out of cooperative relationship with said element,

said driving member eifecflve after the projec-.

driving member; plans, including companion arms mounted on one, oi said members, to shift-- ably support the latch: a projection on one of the companion arms; an element normally movable in imison therewith a yieldable connection i between the element and the driven member whereby the two members are normally actuated in unison; a prominence on the element adapted to cooperate with the projection to normally retain the latch in latching position; and-means to arrest motion oi the element, said yieldable connection permitting the driven member to move after the element has been arrested to thereby cause the projection to move out of cooperative relationship with the prominence, said driving member and said latch having camming surfaces, eiiective upon continued movement of the driving member after the projection has moved out of cooperative relationship with the prominence, to move said latch to disconnect the driving member irom the driven member.

4. In a device of the class described, the combination of a driving member; a driven member; a latch to connect th driven member to the driving member; means to shiftably mount said latch on the driven member; a projection on the mounting means; an element adapted to cooperate with the projection to normally block the latch against unlatching movement; a lost-motion connection between the driven member and the element; yieldabie means to take up the lost motion in one direction; and means cooperating with the element to arrest movement thereof whereupon the lost-motion connection and the yieidable means permit the driven member to move after said element has been arrested to move the projection out of cooperative relationship therewith, said driving member effective after the projection moves out of cooperative relationship with the element, to move the latch to disconnect the driven member from the driving member to position said driven member commensurate with the element and the arresting means.

5. In a device of the class described, the combination of a driven member; a driver to drive the driven member; a latch mechanism shiitably mounted on the driven member; coacting surfaces on the latch mechanism and the driver adapted to form an operating connection therebetween; an element yieldably connected to the arrears tion said driven member commensurate with the element and the arresting means. I

6. In an accounting machine, the combination of a diiferential deviceadapted to be positioned to correspond to difierent numerical values;

means to drive the differential device: latch means carried by the differential device and coacting with the said device to connect said device to the driving means: an element movable in unison with said device, said element contacting the latch means to normally obstruct unlatching movement of the latch means: a yieldable connection between the said device and element; and means to arrest movement of the element to position said element commensurate therewith, whereupon the yieldable connection permits the differential device to move said element a sufficient distance to move the latch out of obstructing relationship with said element; after the element has been arrested, said driving member eifective after the latch has been unobstructed to move said latch to position the differential device commensurate with the element and the arresting means.

7. In an accounting machine having a differential device comprising a driven member and a driving member, the combination of a latch mechanism to connect the driven member to the driving member, said latch mechanism shiftably mounted on said driven member; an element; coacting projections on the latch mechanism and the element; yieldable means to connect the element to the driven member, said yieldable means adapted to urge the driven member and the element in opposite directions to normally maintain the projections in coacting relationship with each other to block unlatching movement of said latch: a stop; means cooperating with the stop to arrest movement of the element, whereupon the yieldable means permits the driven member to continue movement after said element is arrested to move the projection on the latch mechanism out of coasting relationship with the projection on the element; and camming surfaces on the latch mechanism and the driving member, effective when the projections are moved out of coacting relationship with each other, to move the latch mechanism to disconnect the driven member from the driving member to position said driven member commensurate with the arrested pasition of the element and of the position of the 8 P- 8. In a machine of the character described, having a differential device comprising a positionable driven member and a driving member therefor, the combination of a latch to connect the driven member to the driving member; means, including companion arms, to shiftably mount the latch on the driven member; an element; means to form a lost-motion connection between the element and the driven member; a projection on one of the companion arms: a projection on the element arranged to cooperate with the other projection to block unlatching movement of the latch; yieldable means to take up the lost motion between the element and the driven member to normally maintain the projections in cooperative relationship with each other; means to arrest the element, whereupon the yieldable means and the lost-motiton connection permit the driven member to move relatively to said element to move the projection on the arm out of cooperative relationship with the other projection to free the latch for unlatching movement; and coacting camming surfaces on the latch and the driving member, effective when the projections are moved out of cooperative relationship, to move the latch to disconnect the driven member from the driving member to in turn position said driven member commensurate with the position of the element and of the position of the arresting means.

9. In a machine of the class described, having a diiferential device comprising a driven member and a driver to drive the driven member, the combination of a latch to connect the driven member to the driver; companion arms to shiftably support the latch on the driven member; coacting surfaces on the latch and the driver: a first yieldable means to urge the coacting surfaces into engagement with each other to form an operating connection between the driven member and the driver; an element; means to form a lost-motion connection between the element and the driven member; a projection on one of the companion arms; a projection on the element adapted to cooperate with the other projection to retain the coacting surfaces in engagement with each other to form a, positive operating connection between the driven member and the driver; a second yieldable means to take up the lost motion between the element and the driven member to normally maintain the projec tions in cooperative relationship with each other; and means to stop the element after it has completed an extent of movement, after which the lost-motion connection and the second yieldable mean permit the driven member to move a fixed distance, after said element is arrested, to move the projection on the arm out of cooperative relationship with the other projection to free the latch for shifting movement, whereupon the o0- acting surfaces shift said latch to disconnect the driven member from the driver to position said driven member commensurate with the arrested position of the element and the stopping means.

LAURENCE N. LEHMAN. 

